Auckland's record rainfall on Monday saw roads submerged, homes and businesses flooded and left behind a nasty discovery for some residents with raw sewage in their backyards.
Nearly all of Auckland's beaches were deemed unsafe to swim at on Monday in the aftermath due to discharge from pipes.
Auckland Council's SafeSwim website says its water quality models predict that levels of Faecal Indicator Bacteria breach national guidelines for swimming for most beaches, hence its warnings.
Watercare chief operations officer Mark Bourne told AM that large a amount of the stormwater that entered the wastewater system was through manholes.
He said that the current systems in place aren't designed to cope with the amount of rain Auckland saw on Monday.
"Under a normal rainfall event, we don't see the same levels of overflow that occurred yesterday," Bourne said.
"It's purely down to that volume of rain over such a short period of time. Watercare is investing over $10.9 billion in the waste system over the next 10-years, which will reduce the amount of overflow and improve the quality of wastewater that is treated and released into the environment."
One of Watercare's major projects is the central interceptor, which will run for 13km between Western Springs and the Māngere Wastewater Treatment Plant.
The $1.2 billion project announced in 2019 is due to be completed by 2025, which will help reduce sewage overflows into the Waitematā Harbour and help clean up local waterways.
Bourne told AM the central interceptor - which is Watercare's largest infrastructure investment ever in the Auckland region in terms of wastewater system - is one of their major projects but there are more projects ongoing to help reduce stormwater entering the wastewater system.
Bourne said the best thing Aucklanders can do is to check their downpipes to make are connected to the stormwater system rather than the wastewater system.
